The effect of meal feeding and of sham-feeding on insulin secretion in dogs.

After feeding intact conscious dogs 1000 g mashed meat, peripheral venous immunoreactive insulin activity (IRI) increases before any enhancement of amino nitrogen concentration. This course of IRI is paralleled by a decrease of free fatty acids. Meal feeding in dogs, whose pancreatic juice is completely diverted from the gut by a fistula, is followed by a similar IRI increase without a distinct enhancement of amino nitrogen. In oesophagus fistula dogs, sham-feeding meat in 9 out of 15 experiments results in a considerable early IRI increase which is correlated with a small but a significant decrease of blood glucose and free fatty acid concentrations. In these tests there was no amino nitrogen alteration either.